Failure of homogeneous multilayer approximation for transversely nonuniform plasma waveguides

Abstract

A homogeneous multilayer approximation is applied to a two‐dimensional transversely nonuniform cold plasma waveguide. As a result, the homogeneous multilayer modeling for an inhomogeneous slab is shown to be invalid for such plasma waveguides. The propagation constant of the TM mode supported by a multilayered plasma slab is found to diverge at a series of the extended Tonks resonance frequencies corresponding to a series of layer boundaries, that is, plasma density discontinuities. It is indicated that the inhomogeneous multilayer modeling having no density discontinuities can eliminate the above difficulty.